Effect of Heat at Varying Concentrations of Hydrogen Ion on Vitamin B (B1) in Protein-Free Milk

This is the authors' abstract. We don't add key points for this paper.

Vitamin B (old nomenclature) has long been known to be relatively sensitive to heat, particularly in an alkaline medium.As the evidence for the existence of at least two vitamins grew, it seemed apparent that, in yeast extracts particularly, the antineuritic vitamin was the less stable of the two when the extract was heated.This has led to the use of the t,erms "heat-labile antineuritic" and "heat-stable growth-promoting" vitamins for vitamins B (BJ and G (BJ respectively.A full review of the literature will not be included in the present paper inasmuch as Sherman and Smith (1) have adequately brought together the material up to the end of 1931.A few references will be mentioned, however, which show that the stability of vitamin B appears to vary in different media, as has been shown to be the case with vitamin G (B,).As early as 1917 Chick and Hume (2) found that wheat embryo could be heated 2 hours at about 100" without significant loss.However, yeast extract lost about 50 per cent of its potency on being heated 1 hour at 100' and about 70 per cent if heated 2 hours at 122".At 118-124" the vitamin content of wheat embryo was reduced about 75 to 90 per cent on 2 hours of heating.Pigeons were used as the experimental animals and the results, therefore, refer to the antineuritic vitamin.In 1920 Emmett and Luros (3) showed that the antineuritic